GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the HVAC System Check performed?

--

Go to Step 2

Go to HVAC System Check

2

Disconnect the A/C compressor clutch relay.

Does the compressor clutch relay remain engaged?

--

Go to Step 3

Go to Step 5

3

Test for a short to voltage in the BLK/WHT wire between the A/C compressor clutch relay and the A/C compressor clutch.

Does a short to voltage exist?

--

Go to Step 11

Go to Step 4

4

Replace the A/C compressor clutch. Refer to Compressor Clutch Coil and/or Pulley Rim .

Is the repair complete?

--

Go to HVAC System Check

--

5

  1. Reconnect the A/C compressor clutch relay.
  2. Turn the ignition switch to LOCK.
  3. Disconnect the A/C compressor control module connector.
  4. Turn the ignition switch to ON.

Does the A/C compressor clutch engage?

--

Go to Step 6

Go to Step 8

6

Test for a short to ground in the PNK wire between the A/C compressor clutch relay and the A/C compressor control module.

Does a short to ground exist?

--

Go to Step 11

Go to Step 7

7

Replace the A/C compressor clutch relay. Refer to Compressor Relay Replacement .

Is the repair complete?

--

Go to HVAC System Check

--

8

  1. Make sure that the A/C switch is OFF.
  2. Connect a test lamp from A/C compressor control module connector cavity 11 to chassis ground.

Does the test lamp light?

--

Go to Step 10

Go to Step 9

9

Replace the A/C compressor control module. Refer to Air Conditioning (A/C) Compressor Control Module Replacement .

Is the repair complete?

--

Go to HVAC System Check

--

10

Test for a short to voltage in the BLU wire between the A/C switch and the A/C compressor control module.

Does a short to voltage exist?

--

Go to Step 11

Go to Step 12

11

Repair the short. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to HVAC System Check

--

12

Replace the A/C switch. Refer to Control Assembly Replacement .

Is the repair complete?

--

Go to HVAC System Check

--